Field of the Invention
This invention relates generally to medical instruments and devices and methods for their use in diagnostic analysis of biological and other liquid specimens and more particularly, this invention relates to instruments and devices and methods for their use in an automated multiple simultaneous diagnostic analysis, even more particularly this invention relates to vessels for use in diagnostic situations which include structure for preventing movement between the vessel and its carrier.
In a typical diagnostic situation, a sample is taken from a patient, for example blood and placed in a container. The sample is put through various analytical procedures to assist medical personnel in diagnosing an individual""s medical condition. For example, in the case of testing for a patient""s allergic reaction, whole blood is taken from a patient and at least a portion of the whole blood is converted to blood serum for testing.
The blood serum is placed in a vessel, typically a cylindrical vial, having an open proximal end and closed distal end. The vessel having the sample is also known as a sample tube. The sample tube having a proximal end zone defining a sample cup for storing liquid sample. The vessel is placed on a carrier, also know as a carousel and more specifically a sample carousel. Other patient""s sample are also placed on the sample carousel. Well known diagnostic instruments for analyzing such samples include another carousel, known as a diagnostic carousel, arranged in a side-by-side relationship with the sample carousel. Typically, such instruments include a separate transfer mechanism to transfer sample from the sample carousel to containers held by the diagnostic carousel. Examples of such instruments are found in US Patents such as Miyake et al, U.S. Pat. No. 6,197,255 B1 (discloses an example of side-by-side carousels which includes a liquid delivery device for removing the sample from one of the side-by-side carousels and transferring it to the other side-by-side carousel), Sasaki et al, U.S. Pat. No. 6,193,933 (also discloses similar side-by-side carousels in an automatic analysis apparatus), Mitsumaki et al, U.S. Pat. No. 5,320,966 and Wakatake, U.S. Pat. No. 5,183,638.
The containers for holding sample for diagnosis on the diagnosis carousel are known as pipettes. Each of the pipettes and the sample tubes typically include unique identifying indicia. Each pipette is matched to a unique sample tube for testing and analyzing that particular patient""s serum. In the case of testing for allergy, an immunoassay is performed on the liquid sample.
The unique identifying indicia is typically machine readable and using a proper apparatus, the diagnostic instrument is able to align the pipette and the sample tube for accurate transfer of the sample to the pipette. In typical fashion, each of the carousels rotates to the alignment point because the carousels are typically rotatable. Examples of such rotatable carousels are found at Minekane, U.S. Pat. No. 4,906,433 and Berglund, U.S. Pat. No. 4,459,265 (side-by-side carousels combined with an offset platform for liquid analysis).
In practice, the unique identifying indicia must be placed on the carousel at the correct angular relationship to the machine reader or else the machine reader is unable to identify the indicia accurately and the entire process stops being automated and becomes manual. This is especially so for the sample tubes as compared with the pipettes. The sample tubes as noted above are in the shape of a cylindrical vial and easily lend themselves to rotational movement in response to the rotational forces caused by the rotation of the sample carousel.
Additionally, initial placement of the sample tubes on the sample carousel must be accurate as well. A failure to initially accurately place the sample tubes on the sample carousel will also result in misreadings or a complete stoppage of the automated process.
Additionally, as the sample carousel is handled from one location to another can also result in movement of the sample tubes relative to the sample carousel. Shaking or jostling of the carousel as it is moved onto the diagnostic instrument can easily cause the angular positioning of the unique identifying indicia to change sufficiently to cause misreadings or a complete stoppage of the automated process.
In an effort to promote correct angular positioning of the sample tubes relative to the machine reader, others have attempted various structures. For example, as shown in FIG. 1 (Prior Art), a series of samples tubes 114 is shown being carried by a sample carousel 112. The sample tubes have an annulus adjacent the open proximal end. The annulus 116 rests upon compatible structure of the sample carousel 112. It will be noted that the typical structure of the mating structures of the sample tube and carousel are provided with a generally smooth surface. Rotation of the sample tubes, a change in the angular positioning of the sample tubes relative to the sample carousel, readily takes as illustrated by arrows 120. This clearly so in response to the rotation of the sample carousel 112 as indicated by arrow 122. However, any movement of the sample carousel 112 may well cause a change in angular positioning of the sample tube relative to the sample carousel sufficient for the machine reader to be unable to correctly identify the unique identifying indicia.
Others have attempted to increase the friction between abutting surfaces of the sample tube and sample carousel by adding rubber or springs or some combination there of to the annulus surface. While these attempts probably do have some beneficial effect, it is not sufficient to ensure the type of reliability necessary for the smooth automated operation of the testing required. Additionally, such structures do not assist in the initial and correct angular placement of the sample tube on the sample carousel. And, such structures increase the cost of manufacture as a result of the additional manufacturing step to affix the rubber and/or springs.
What is needed is structure that enables a sample tube to be correctly and securely positioned on the sample carousel to avoid misreadings or a complete stoppage of the automated diagnostic process. All of this is necessary while reducing the cost of such devices.
It is an object of this invention to provide a simple and efficient structure to assist with initial and secure placement of a sample tube on a sample carousel.
It is an additional object of this invention to provide such a structure that be resistant to movement of the sample tube on the sample carousel during handling to ensure correct angular position for reading each sample tube""s unique identifying indicia.
It is an additional object of this invention to provide such a structure which is both easy to use and to manufacture as well as being cost effective.
This invention is directed toward a structure for secure placement of a sample tube on a sample carousel. The sample tube includes a first open proximal end and a second closed distal end. Between the ends and located adjacent the proximal end, the sample tube includes a radially outwardly extending annulus having an abutment surface. The abutment surface includes anti-rotational structure.
The invention in an exemplary embodiment includes a sample carousel having an outer periphery zone having a plurality of openings. The openings are sized and shaped for compatible sliding engagement with the sample tube and adjacent the openings are abutment surfaces. Each abutment surface includes anti-rotational structure and the anti-rotational structure is sized and shaped for compatible mating engagement with the sample tube anti-rotation structure.
Upon engagement of the respective anti-rotational structures, the sample is secured against relative angular positioning. Thus, once the sample tube is slidably engaged with the sample carousel, there is a secure connection preventing relative angular movement of the sample tube with respect to the sample carousel. It will be appreciated that the slidable connection is not affected by the anti-rotational structure in terms of engaging and disengaging the sample tube from the sample carousel. It will also be appreciated that the anti-rotational structure assists in the initial placement of the sample tube to the sample carousel because of the secure and positive connection made between the two.
In accordance with the above objects and those that will be mentioned and will become apparent below, the anti-rotational apparatus for securing a sample tube to a carousel in accordance with this invention comprises:
a sample tube having an open proximal end and a closed distal end, the sample tube having an annulus adjacent the proximal end, the annulus being radially outwardly projecting and including an anti-rotational structure; and
a carousel designed for rotation and having openings for carrying a plurality of sample tubes, at least one of the openings including compatible and mating anti-rotational structure for mating with the anti-rotational structure of the sample tube,
wherein, the anti-rotational apparatus comprises the combination of the sample tube and the carousel anti-rotational structures.
In an exemplary embodiment of the sample tube includes unique identifying indicia which is machine readable. Once the sample tube is placed in the carousel, the indicia is placed at the correct angular position to be read by the machine reader. The anti-rotational apparatus as described above and more fully below, secure the indicia in angular position so that the machine makes an accurate and reliable reading of the indicia. In an additional exemplary embodiment, the indicia comprises a bar code and the machine reader comprises a bar code reader.
In still an additional exemplary embodiment, the anti-rotational structures of each of the sample tube and sample carousel comprise male and female teeth pattern. In a more detailed exemplary embodiment, the teeth patterns are mating gear teeth.
An additional preferred embodiment includes the method in accordance with this invention of securing a sample tube to a rotatable carouse for preventing movement of the sample relative to the carousel, the steps comprising:
placing a sample tube having anti-rotational structure on a carousel having compatible anti-rotational structure; and
mating the anti-rotational structures of the sample tube and the carousel before rotating the carousel.
It is an advantage of this invention to a provide anti-rotational structure on the sample tube to promote secure connection of the sample tube and the sample carousel for accurate and reliable automated reading of the unique machine readable identifying indicia on the sample tube.
It is another advantage of this invention to provide such anti-rotational structure on the sample tube and carousel that promotes initial correct placement of the sample tube on the sample carousel.
It is another advantage of this invention to provide such anti-rotational structure to ensure the smooth operation of the automated diagnostic process.